crowell



Jan. 4, 1927. Re. "16,516

- E. v. CROWELL APPARATUS FOR AND METHOD 0F ('EMENTING OIL WELL CSINGS Oxginajb Filed Junev l5. 1920 INVENToR f/ l/. C'rwrcV/ BY WMM/WA ATTORNEY Reissued Jan. 4, 1927.

UNITED STATE-:s

Vr'arl-:la'rf foFFlcE.

man v. onownnr., or Los ANGELES, CALIFORNIA.. l

APPARATUS FOR AND 'METHOD 0F CEMENTING OIL-WELL CASINOS.

Original No. 1,502,179, dated July 22, 1924, Serial No. iiled June 29, 1926.

My invention relates to improvements in well casings, particularly those of the type employed in oil and gas. wells, and 1t consists in the constructions, combinations and arrangements herein described and claimed One of the objects of the invention is to provide a cementing shoe for use. in connection with an oil or gas well casing, by means of which a cementing mixture, as for example mud-Huid, can be ejected from the casing string or oil string to fill the space between the string and well bore and thus seal the formation seatagainst the seepage of'water.

Another object .of this invention is` to provide a device which is adapted to beL placed any place in a string of cas1 n as a coupling member between adjacent joints of casing or as a true section of the strlng. l .A further object of the invention is to provide means in oil or gas well constructions, enabling the making of a water-tight seal between the casing and rock formation independently of the casing shoe on the lowermost extremity of the oil string or the texture of the landingformation on'which the shoe rests. f

A further and important' object of. the 1n vention is to provide a valve mechanism forming .part of the well casing, throu h which the mud-fluid is ejected e casing.

vA further object of the invention is to provide a construction by means ofwhich the cementing material may beintroduced around the casing while the latter rests on its formation seat before the oil or gas sand has been opened, the entire casing being employed in carrying out this mode of 'op- Y eration.

Another object of the invention is t adopt a method of carrying out the foregoing objects.`

' Other objects of my invention will appear in the following specification reference beingv had to the accompanying drawings, in which: j

Fig. 1 is a longitudinal section illustrating the improved cementing apparatus wherein the whole casing is employed in discharging the 'cementing material, and- Fig. 2 is a detail section of the same structure.

This application is principally concerned hind t e l of alternating layers o 389,151, led .Tune 15, 1920. Application for reissue Serial No. 119.486.

with that form of the invention wherein the entire casing is employed during the operation of discharging the cementing material, another apparatus for the same purpose being disclosed in my Patent No. 1,432,017, October 17 1922, which is a division of this application.

In order that the reader might be able to more fully appreciate the purpose of the invention, it is thought well to preface the description of the construction and mode of operation by a'brief description of oil well casing operation. Casing, as now used in oil field operations is either iron or steel tubular pipe, the kinds and sizes thereof differing considerably in various fields, all according to the peculiar conditions encountered.

A complete column of pipe or casing-as placed in the bore of oil wells, is common- 1y referred to as the string of casing. The fundamental purpose of the oil well casing is that of protection, that is to say, to keep the water and other vforeign substances from falling into the shot hole at the bottom and thereby'either crowding the oil back from the bore or obstructing the lower'end of the bore in such a manner that neither oil nor gas can flow.

In drilling oil or gas wells, the formations passed through as the de th increases consist and occasionarlly a stratum of sand. The shale layers predominate over the lime layers as regards number and thickness, andv again, the lime layers predominate over the sand layers in the same manner. Usually the underground water finds its channels of flow inthe lime or sand strata, the water flowing through the sand stratum gnerally above or below a lime stratum.

lAs the depth of the hole is increased durlime-stone, shale, A

ing'the drilling operation, Water reducing lime or sand strata are encounters the water thus released by the puncturing ofthe strata by the drill point, settli l (in the hole and lilling it with water. Thxgdrilling operations are thus greatly retarded', due tothe cushioning eiiect the water has on the drilling operation of the tools.

Again, the water released from the lime strata washes down over the shale strata below, causing thel shale to cave, Slough out and fall down the hole. A loose shale fornon mation may thus cave to such an extent as to even entirely bury the tools. An enormousamount of additional work is required in thereafter excavating the material and recovering the tools".

' With this brief survey in mind, the need for the improvement which the invention otlers will be understood. The invention relates to a construction by which the sealing of a casin in a bore may be performed before the oil or gas stratum has been opened. The oil string comprises several casing sections l, which occupy a substantially central position in the well bore B, the -casing shoe 2 at the lowerlnost extremity resting on an annular rojection of rock or other material, eommony known as the formation seat S. The bore of the well is ultimately intended to communicate with what is known as the shot hole (not shown) but accordin to the invention the bore is cemented efore such tablished.

Carried by the casing l is the cementing shoe 3 which is secured to adjacent sections by couplings 5a. The cementing shoe 3i is very much like one of the sections of the well casing. Two or more valves 7 normally close ports 8l in the annular enlargement -9l of the `shoe 3a, each being held in place by rather owerful leaf springs` suggested at 10a and) clearly shown in my patent referred to.

A section of tubing 25 is let down through the casing 1 until the lower end strlkes the bottom of rthe bore B. This tubing hasa 'belt of perforations 35' out of which fluid tween the tubing 2'5'L and the casin l, t'wo of such packers 36 being shown, owever, only the upper rubber having been expanded .into engagement with the casing.

The method of operation may readily ybe understood 'from the foregoing description. The casing l is let down into the bore until the shoe engages and rests upon the formation S. The cementing shoe 3n is introduced in the casing il*L at the desired location from the bottom, the mud fluid outlet Valve 71 being normally held closed by the leaf springs mentioned. The tubing 25a with its packer mechanisms 36 is lowered into the casing until it strikes the closed bottom of the bore.

Mud Huid or other cementing material-is then introduced into the tubing 25 whence it escapes at the erforations 35. The casl ing 1 fills up to t e packers 36 the pressure of subsequently iniowing cement forcin the valves 7 open so that the bore becomes led as shown. The injector tubing 25 is with communication is esy drawn while vthe cement inside the casing is yet plastic. The cement inside the casing may be removed by suitable means, but that outside of the casing remains in place.

Iclaim: l

1. Means for sealing a well before opening the bore into a productive stratum, comprising a well casing with a plurality of valved ports; and tubing let'down in the casing, with packing means for securinga joint therebetween and the casing, having perforationsthrough which sealing material is ejected to lill the casing up to the packing means, and then escape through said ports to fill the surrounding bore.

2. Means for sealing a Well before opening the bore into a productive stratum, comprlsing a well casing composed of sections and including a ported cementing shoe; tubing let down in the casing, having openings through which sealing material is ejected into the casing; and valves controlling the ports,enabling the material to flow out of the casing into vthe bore but not back.

3. The method of sealing a well consisting of lowering a casing wit-h an lopening into the bore of a well and resting it permanently on the formation seat, inserting a cement injectorv into the casing until "it strikes the bottom of ythe bore, introducing cement by said' injector into the inside of the casing until it reaches and flows through the opening and into the bore, withdrawing tl1c',injector while the cement is yet plastic, l

and preventing the return of the cement from the bore through said opening.

4. The method of sealing a well consisting of lowering a casing with an opening into the bore of a well and resting it permanently on the formation seat, inserting a perforated cement injector into the casing until it too rests on the formation seat, introducing cement into said injector causing it to flow out' of said perforation. into the casing thence through the opening and into the bore, withdrawing the injector while the cement is yet plastic, and preventing thereturn of the cement from the bore through said opening. i

5. Well cementing means comprising casing having normally closed ports adapted to be opened by pressure of material in the casing for discharge of said material outwardly through said ports, and ymeans below the ports for closing the space between the bore of a Well and the space outside of the casing.

6. Well cementing means comprising casing having normally closed ports'adapted to be opened by pressure of material in the casing, and means below said ports for closing communication between the bore of the casing and the `space outside of the casing.

7. Well cementing means comprisin a cementing barrel forming a fixedv sectlon of well casing and having ports adapted for and operated 'b matenalin sai.

ing, said section space between a well, check discharge. of material into the the casing'and the bore off valves controllin said ports, flow said ports or closing communication .5 between said space and the boreof the cas- 8. A well casing including 'a ported xed section having normally closed ports, 4auto'-` matic valve means controlling said ports en- -l0 abling 'introduction of sealing material p' said-section into the space between throughy the casing and a well bore and preventing 9. A device of the character described 15 comprising a fixed section o f well casing arranged for coupling toa ing,A said section havin an valve means normal y closing said ports pressure of Iiluentsealing section to open the' latter to permit outward passage of said material. 10. A device of the character described comprising ya fixed sectinI of well casing arranged for couplin to a string of well casavin peripheral ports, and outwardly opening c eck valves controlling said ports.

11. 'In combination with a strin casing,

string of well cassaid section having peripheral rts, and valve means normally closing said ports and operated by pressure ofv fiuent'material in said section to and means be-` vperipheral ports,

Qf wen' a fixed section coupled Vt eretoto. form a portion of said string,

open the latter to permit outward passage of said material.

12. In combination Awith a strin of well casing, a lixedfsection coupled t ereto to form a portion 4ozI said string, said Asection having peripheral ports,` and outwardly openin check valves controlling said ports.

13. combination with a well casingdisposed in a rwell bore, of means for creating a surrounding barrierV between the well casing andthe bore at a, desired point, comprising a valve structure disposed at a pointv along the length of the shaft, said valve structure having a port communicating with the exterior of theuas-ng,l and a check valve acting to permit the cementitious material to be forced outwardly from the casing throu h the ort. f

- 14.' n com ination with a string of casing dispsed within a well bore. means forming a ed section of the string for 'creating a surrounding barrier between the casing and the bore comprisingl a valve structure to be interposed between engthsof casing to permit cementitious material to be forced from within the casing to the space4 within'the bore surrounding the casing and including automaticv valve means for. preventing the backflow of the cementitiousl material into thel'casing. y f S'gned at Los Angeles, in the county of Los Angeles, this 15th 'da of June, 1926.

, ERD .oRowELL 

